Exemplary aspects of the present invention relate to projectors and more particularly to a projector in which a cooling fluid is circulated in order to cool down the light source.
Related art projectors have had an increase in brightness and reduction in size, increasing the in-device heat density. For this reason, further enhancement of cooling performance is required for the cooling device to cool the light source as a heat generation source and the light valve to be heated by suffering emission light of the light source. In such circumstances, the situation is true for the projector using light-emitting diodes (LEDs), or light-emitting elements, in the light source, requiring to further enhance the cooling performance.
In the case of a related art projector using light-emitting diodes (LEDs), or light-emitting elements, in the light source, there is a proposal of a lighting device to be used as a light source of the projector by outputting illumination light having a light intensity distribution uniform on the illumination plane by use of an LED-arrayed panel arranging a plurality of LED elements (JP-A-2002-374004).
In the case of a related art projector using a cathode ray tube, there is a proposal of a device that a cooling tank is provided contacting with the surface of a cathode ray tube to display images and a cooling liquid is filled therein so that the cooling liquid can be circulated to the cooling tank through a circulation mechanism thereby lowering the temperature of the cathode ray tube (JP-A-8-242463).
In the case of a related art liquid-crystal projector to illuminate the light from the light source onto the liquid-crystal panel and thereby project a display image on the liquid-crystal panel to a screen, a transparent cooling medium vaporable by heat is sealed within a vessel forming on both surfaces of transparent regions greater in area than the display region of the liquid-crystal panel. This vessel is provided with a cooler having a vaporization refrigerant container chamber for the cooling medium vaporized by absorbing heat to again liquefy and release heat externally of the vessel. By arranging a liquid-crystal panel over the surface of the cooler, the heat generated on the liquid-crystal panel is cooled down (JU-A-1-75288).